Tracking the Number of Children Identified with Autism Spectrum Disorders

(FROM CENTERS FOR DISEASE AND CONTROL)

CDC’s National Center on Birth Defects and Developmental Disabilities has been tracking ASDs for over a decade through the Autism and Developmental Disabilities Monitoring (ADDM) Network. The newest estimates from the ADDM Network are based on data collected in 14 areas of the United States during 2008. These 14 communities comprised over eight percent of the United States population of 8-year-olds in 2008. Information was collected on children who were 8 years old because previous work has shown that, by this age, most children with ASDs have been identified for services.

CDC estimates 1 in 88 children (11.3 per 1,000) has been identified with an autism spectrum disorder (ASD).

This marks a 23% increase since our last report in 2009. And, a 78% increase since our first report in 2007. Some of the increase is due to the way children are identified, diagnosed and served in their local communities, although exactly how much is due to these factors in unknown.

The number of children identified with ASDs varied widely across the 14 ADDM Network sites, from 1 in 47 (21.2 per 1,000) to 1 in 210 (4.8 per 1,000).

ASDs are almost 5 times more common among boys (1 in 54) than among girls (1 in 252).

The largest increases over time were among Hispanic children (110%) and black children (91%). We suspect that some of this increase is due to greater awareness and better identification among these groups. However, this finding explains only part of the increase over time, as more children are being identified in all groups.

There were increases over time among children without intellectual disability (those having IQ scores above 70), although there were also increases in the estimated prevalence of ASDs at all levels of intellectual ability.

More children are being diagnosed at earlier ages—a growing number of them by age 3. Still,most children are not diagnosed until after they reach age 4, even though early identification and intervention can help a child access services and learn new skills. This is why CDC’s Learn the Signs. Act Early.program is essential. Through this program, CDC provides free tools to help parents track their child’s development and free resources for doctors and educators. CDC is also working with states and communities to improve early identification.